Uses the ext4 file system --> "LUKS encryption and decryption: In the cryptsetup-laboratory with Termux (running under the Android 11 operating system), "cryptsetup reencrypt --disable-locks --type luks2", no root access, no loop device, and an unusable "mount" command.": https://old.reddit.com/r/termux/comments/18am78j/luks_encryp... (old.reddit.com/r/termux/comments/18am78j/luks_encryption_and_decryption_in_the/)